| 1 | /* |
| 2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include <fcntl.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <stdio.h> |
| 12 | #include <string.h> |
| 13 | #include <unistd.h> |
| 14 | #include <inttypes.h> |
| 15 | #include <sys/types.h> |
| 16 | |
| 17 | #include <common/common.h> |
| 18 | #include <common/trace-chunk.h> |
| 19 | #include <common/kernel-ctl/kernel-ctl.h> |
| 20 | #include <common/kernel-ctl/kernel-ioctl.h> |
| 21 | #include <common/sessiond-comm/sessiond-comm.h> |
| 22 | #include <common/tracker.h> |
| 23 | #include <common/utils.h> |
| 24 | #include <lttng/event.h> |
| 25 | #include <lttng/lttng-error.h> |
| 26 | #include <lttng/tracker.h> |
| 27 | |
| 28 | #include "lttng-sessiond.h" |
| 29 | #include "lttng-syscall.h" |
| 30 | #include "consumer.h" |
| 31 | #include "kernel.h" |
| 32 | #include "kernel-consumer.h" |
| 33 | #include "kern-modules.h" |
| 34 | #include "utils.h" |
| 35 | #include "rotate.h" |
| 36 | #include "modprobe.h" |
| 37 | #include "tracker.h" |
| 38 | |
| 39 | /* |
| 40 | * Key used to reference a channel between the sessiond and the consumer. This |
| 41 | * is only read and updated with the session_list lock held. |
| 42 | */ |
| 43 | static uint64_t next_kernel_channel_key; |
| 44 | |
| 45 | static const char *module_proc_lttng = "/proc/lttng"; |
| 46 | |
| 47 | static int kernel_tracer_fd = -1; |
| 48 | |
| 49 | #include <lttng/userspace-probe.h> |
| 50 | #include <lttng/userspace-probe-internal.h> |
| 51 | /* |
| 52 | * Add context on a kernel channel. |
| 53 | * |
| 54 | * Assumes the ownership of ctx. |
| 55 | */ |
| 56 | int kernel_add_channel_context(struct ltt_kernel_channel *chan, |
| 57 | struct ltt_kernel_context *ctx) |
| 58 | { |
| 59 | int ret; |
| 60 | |
| 61 | assert(chan); |
| 62 | assert(ctx); |
| 63 | |
| 64 | DBG("Adding context to channel %s", chan->channel->name); |
| 65 | ret = kernctl_add_context(chan->fd, &ctx->ctx); |
| 66 | if (ret < 0) { |
| 67 | switch (-ret) { |
| 68 | case ENOSYS: |
| 69 | /* Exists but not available for this kernel */ |
| 70 | ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE; |
| 71 | goto error; |
| 72 | case EEXIST: |
| 73 | /* If EEXIST, we just ignore the error */ |
| 74 | ret = 0; |
| 75 | goto end; |
| 76 | default: |
| 77 | PERROR("add context ioctl"); |
| 78 | ret = LTTNG_ERR_KERN_CONTEXT_FAIL; |
| 79 | goto error; |
| 80 | } |
| 81 | } |
| 82 | ret = 0; |
| 83 | |
| 84 | end: |
| 85 | cds_list_add_tail(&ctx->list, &chan->ctx_list); |
| 86 | ctx->in_list = true; |
| 87 | ctx = NULL; |
| 88 | error: |
| 89 | if (ctx) { |
| 90 | trace_kernel_destroy_context(ctx); |
| 91 | } |
| 92 | return ret; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Create a new kernel session, register it to the kernel tracer and add it to |
| 97 | * the session daemon session. |
| 98 | */ |
| 99 | int kernel_create_session(struct ltt_session *session) |
| 100 | { |
| 101 | int ret; |
| 102 | struct ltt_kernel_session *lks; |
| 103 | |
| 104 | assert(session); |
| 105 | |
| 106 | /* Allocate data structure */ |
| 107 | lks = trace_kernel_create_session(); |
| 108 | if (lks == NULL) { |
| 109 | ret = -1; |
| 110 | goto error; |
| 111 | } |
| 112 | |
| 113 | /* Kernel tracer session creation */ |
| 114 | ret = kernctl_create_session(kernel_tracer_fd); |
| 115 | if (ret < 0) { |
| 116 | PERROR("ioctl kernel create session"); |
| 117 | goto error; |
| 118 | } |
| 119 | |
| 120 | lks->fd = ret; |
| 121 | /* Prevent fd duplication after execlp() */ |
| 122 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 123 | if (ret < 0) { |
| 124 | PERROR("fcntl session fd"); |
| 125 | } |
| 126 | |
| 127 | lks->id = session->id; |
| 128 | lks->consumer_fds_sent = 0; |
| 129 | session->kernel_session = lks; |
| 130 | |
| 131 | DBG("Kernel session created (fd: %d)", lks->fd); |
| 132 | |
| 133 | /* |
| 134 | * This is necessary since the creation time is present in the session |
| 135 | * name when it is generated. |
| 136 | */ |
| 137 | if (session->has_auto_generated_name) { |
| 138 | ret = kernctl_session_set_name(lks->fd, DEFAULT_SESSION_NAME); |
| 139 | } else { |
| 140 | ret = kernctl_session_set_name(lks->fd, session->name); |
| 141 | } |
| 142 | if (ret) { |
| 143 | WARN("Could not set kernel session name for session %" PRIu64 " name: %s", |
| 144 | session->id, session->name); |
| 145 | } |
| 146 | |
| 147 | ret = kernctl_session_set_creation_time(lks->fd, session->creation_time); |
| 148 | if (ret) { |
| 149 | WARN("Could not set kernel session creation time for session %" PRIu64 " name: %s", |
| 150 | session->id, session->name); |
| 151 | } |
| 152 | |
| 153 | return 0; |
| 154 | |
| 155 | error: |
| 156 | if (lks) { |
| 157 | trace_kernel_destroy_session(lks); |
| 158 | trace_kernel_free_session(lks); |
| 159 | } |
| 160 | return ret; |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * Create a kernel channel, register it to the kernel tracer and add it to the |
| 165 | * kernel session. |
| 166 | */ |
| 167 | int kernel_create_channel(struct ltt_kernel_session *session, |
| 168 | struct lttng_channel *chan) |
| 169 | { |
| 170 | int ret; |
| 171 | struct ltt_kernel_channel *lkc; |
| 172 | |
| 173 | assert(session); |
| 174 | assert(chan); |
| 175 | |
| 176 | /* Allocate kernel channel */ |
| 177 | lkc = trace_kernel_create_channel(chan); |
| 178 | if (lkc == NULL) { |
| 179 | goto error; |
| 180 | } |
| 181 | |
| 182 | DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d", |
| 183 | chan->name, lkc->channel->attr.overwrite, |
| 184 | lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf, |
| 185 | lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval, |
| 186 | lkc->channel->attr.live_timer_interval, lkc->channel->attr.output); |
| 187 | |
| 188 | /* Kernel tracer channel creation */ |
| 189 | ret = kernctl_create_channel(session->fd, &lkc->channel->attr); |
| 190 | if (ret < 0) { |
| 191 | PERROR("ioctl kernel create channel"); |
| 192 | goto error; |
| 193 | } |
| 194 | |
| 195 | /* Setup the channel fd */ |
| 196 | lkc->fd = ret; |
| 197 | /* Prevent fd duplication after execlp() */ |
| 198 | ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC); |
| 199 | if (ret < 0) { |
| 200 | PERROR("fcntl session fd"); |
| 201 | } |
| 202 | |
| 203 | /* Add channel to session */ |
| 204 | cds_list_add(&lkc->list, &session->channel_list.head); |
| 205 | session->channel_count++; |
| 206 | lkc->session = session; |
| 207 | lkc->key = ++next_kernel_channel_key; |
| 208 | |
| 209 | DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")", |
| 210 | lkc->channel->name, lkc->fd, lkc->key); |
| 211 | |
| 212 | return 0; |
| 213 | |
| 214 | error: |
| 215 | if (lkc) { |
| 216 | free(lkc->channel); |
| 217 | free(lkc); |
| 218 | } |
| 219 | return -1; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Compute the offset of the instrumentation byte in the binary based on the |
| 224 | * function probe location using the ELF lookup method. |
| 225 | * |
| 226 | * Returns 0 on success and set the offset out parameter to the offset of the |
| 227 | * elf symbol |
| 228 | * Returns -1 on error |
| 229 | */ |
| 230 | static |
| 231 | int extract_userspace_probe_offset_function_elf( |
| 232 | const struct lttng_userspace_probe_location *probe_location, |
| 233 | uid_t uid, gid_t gid, uint64_t *offset) |
| 234 | { |
| 235 | int fd; |
| 236 | int ret = 0; |
| 237 | const char *symbol = NULL; |
| 238 | const struct lttng_userspace_probe_location_lookup_method *lookup = NULL; |
| 239 | enum lttng_userspace_probe_location_lookup_method_type lookup_method_type; |
| 240 | |
| 241 | assert(lttng_userspace_probe_location_get_type(probe_location) == |
| 242 | LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION); |
| 243 | |
| 244 | lookup = lttng_userspace_probe_location_get_lookup_method( |
| 245 | probe_location); |
| 246 | if (!lookup) { |
| 247 | ret = -1; |
| 248 | goto end; |
| 249 | } |
| 250 | |
| 251 | lookup_method_type = |
| 252 | lttng_userspace_probe_location_lookup_method_get_type(lookup); |
| 253 | |
| 254 | assert(lookup_method_type == |
| 255 | LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF); |
| 256 | |
| 257 | symbol = lttng_userspace_probe_location_function_get_function_name( |
| 258 | probe_location); |
| 259 | if (!symbol) { |
| 260 | ret = -1; |
| 261 | goto end; |
| 262 | } |
| 263 | |
| 264 | fd = lttng_userspace_probe_location_function_get_binary_fd(probe_location); |
| 265 | if (fd < 0) { |
| 266 | ret = -1; |
| 267 | goto end; |
| 268 | } |
| 269 | |
| 270 | ret = run_as_extract_elf_symbol_offset(fd, symbol, uid, gid, offset); |
| 271 | if (ret < 0) { |
| 272 | DBG("userspace probe offset calculation failed for " |
| 273 | "function %s", symbol); |
| 274 | goto end; |
| 275 | } |
| 276 | |
| 277 | DBG("userspace probe elf offset for %s is 0x%jd", symbol, (intmax_t)(*offset)); |
| 278 | end: |
| 279 | return ret; |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * Compute the offsets of the instrumentation bytes in the binary based on the |
| 284 | * tracepoint probe location using the SDT lookup method. This function |
| 285 | * allocates the offsets buffer, the caller must free it. |
| 286 | * |
| 287 | * Returns 0 on success and set the offset out parameter to the offsets of the |
| 288 | * SDT tracepoint. |
| 289 | * Returns -1 on error. |
| 290 | */ |
| 291 | static |
| 292 | int extract_userspace_probe_offset_tracepoint_sdt( |
| 293 | const struct lttng_userspace_probe_location *probe_location, |
| 294 | uid_t uid, gid_t gid, uint64_t **offsets, |
| 295 | uint32_t *offsets_count) |
| 296 | { |
| 297 | enum lttng_userspace_probe_location_lookup_method_type lookup_method_type; |
| 298 | const struct lttng_userspace_probe_location_lookup_method *lookup = NULL; |
| 299 | const char *probe_name = NULL, *provider_name = NULL; |
| 300 | int ret = 0; |
| 301 | int fd, i; |
| 302 | |
| 303 | assert(lttng_userspace_probe_location_get_type(probe_location) == |
| 304 | LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT); |
| 305 | |
| 306 | lookup = lttng_userspace_probe_location_get_lookup_method(probe_location); |
| 307 | if (!lookup) { |
| 308 | ret = -1; |
| 309 | goto end; |
| 310 | } |
| 311 | |
| 312 | lookup_method_type = |
| 313 | lttng_userspace_probe_location_lookup_method_get_type(lookup); |
| 314 | |
| 315 | assert(lookup_method_type == |
| 316 | LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT); |
| 317 | |
| 318 | |
| 319 | probe_name = lttng_userspace_probe_location_tracepoint_get_probe_name( |
| 320 | probe_location); |
| 321 | if (!probe_name) { |
| 322 | ret = -1; |
| 323 | goto end; |
| 324 | } |
| 325 | |
| 326 | provider_name = lttng_userspace_probe_location_tracepoint_get_provider_name( |
| 327 | probe_location); |
| 328 | if (!provider_name) { |
| 329 | ret = -1; |
| 330 | goto end; |
| 331 | } |
| 332 | |
| 333 | fd = lttng_userspace_probe_location_tracepoint_get_binary_fd(probe_location); |
| 334 | if (fd < 0) { |
| 335 | ret = -1; |
| 336 | goto end; |
| 337 | } |
| 338 | |
| 339 | ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name, |
| 340 | uid, gid, offsets, offsets_count); |
| 341 | if (ret < 0) { |
| 342 | DBG("userspace probe offset calculation failed for sdt " |
| 343 | "probe %s:%s", provider_name, probe_name); |
| 344 | goto end; |
| 345 | } |
| 346 | |
| 347 | if (*offsets_count == 0) { |
| 348 | DBG("no userspace probe offset found"); |
| 349 | goto end; |
| 350 | } |
| 351 | |
| 352 | DBG("%u userspace probe SDT offsets found for %s:%s at:", |
| 353 | *offsets_count, provider_name, probe_name); |
| 354 | for (i = 0; i < *offsets_count; i++) { |
| 355 | DBG("\t0x%jd", (intmax_t)((*offsets)[i])); |
| 356 | } |
| 357 | end: |
| 358 | return ret; |
| 359 | } |
| 360 | |
| 361 | static |
| 362 | int userspace_probe_add_callsite( |
| 363 | const struct lttng_userspace_probe_location *location, |
| 364 | uid_t uid, gid_t gid, int fd) |
| 365 | { |
| 366 | const struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL; |
| 367 | enum lttng_userspace_probe_location_lookup_method_type type; |
| 368 | int ret; |
| 369 | |
| 370 | lookup_method = lttng_userspace_probe_location_get_lookup_method(location); |
| 371 | if (!lookup_method) { |
| 372 | ret = -1; |
| 373 | goto end; |
| 374 | } |
| 375 | |
| 376 | type = lttng_userspace_probe_location_lookup_method_get_type(lookup_method); |
| 377 | switch (type) { |
| 378 | case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF: |
| 379 | { |
| 380 | struct lttng_kernel_event_callsite callsite; |
| 381 | uint64_t offset; |
| 382 | |
| 383 | ret = extract_userspace_probe_offset_function_elf(location, |
| 384 | uid, gid, &offset); |
| 385 | if (ret) { |
| 386 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 387 | goto end; |
| 388 | } |
| 389 | |
| 390 | callsite.u.uprobe.offset = offset; |
| 391 | ret = kernctl_add_callsite(fd, &callsite); |
| 392 | if (ret) { |
| 393 | WARN("Failed to add callsite to ELF userspace probe."); |
| 394 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 395 | goto end; |
| 396 | } |
| 397 | break; |
| 398 | } |
| 399 | case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT: |
| 400 | { |
| 401 | int i; |
| 402 | uint64_t *offsets = NULL; |
| 403 | uint32_t offsets_count; |
| 404 | struct lttng_kernel_event_callsite callsite; |
| 405 | |
| 406 | /* |
| 407 | * This call allocates the offsets buffer. This buffer must be freed |
| 408 | * by the caller |
| 409 | */ |
| 410 | ret = extract_userspace_probe_offset_tracepoint_sdt(location, |
| 411 | uid, gid, &offsets, &offsets_count); |
| 412 | if (ret) { |
| 413 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 414 | goto end; |
| 415 | } |
| 416 | for (i = 0; i < offsets_count; i++) { |
| 417 | callsite.u.uprobe.offset = offsets[i]; |
| 418 | ret = kernctl_add_callsite(fd, &callsite); |
| 419 | if (ret) { |
| 420 | WARN("Failed to add callsite to SDT userspace probe"); |
| 421 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 422 | free(offsets); |
| 423 | goto end; |
| 424 | } |
| 425 | } |
| 426 | free(offsets); |
| 427 | break; |
| 428 | } |
| 429 | default: |
| 430 | ret = LTTNG_ERR_PROBE_LOCATION_INVAL; |
| 431 | goto end; |
| 432 | } |
| 433 | end: |
| 434 | return ret; |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * Extract the offsets of the instrumentation point for the different lookup |
| 439 | * methods. |
| 440 | */ |
| 441 | static |
| 442 | int userspace_probe_event_add_callsites(struct lttng_event *ev, |
| 443 | struct ltt_kernel_session *session, int fd) |
| 444 | { |
| 445 | int ret; |
| 446 | const struct lttng_userspace_probe_location *location = NULL; |
| 447 | |
| 448 | assert(ev); |
| 449 | assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE); |
| 450 | |
| 451 | location = lttng_event_get_userspace_probe_location(ev); |
| 452 | if (!location) { |
| 453 | ret = -1; |
| 454 | goto end; |
| 455 | } |
| 456 | |
| 457 | ret = userspace_probe_add_callsite(location, session->uid, session->gid, |
| 458 | fd); |
| 459 | if (ret) { |
| 460 | WARN("Failed to add callsite to userspace probe event '%s'", |
| 461 | ev->name); |
| 462 | } |
| 463 | |
| 464 | end: |
| 465 | return ret; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | * Create a kernel event, enable it to the kernel tracer and add it to the |
| 470 | * channel event list of the kernel session. |
| 471 | * We own filter_expression and filter. |
| 472 | */ |
| 473 | int kernel_create_event(struct lttng_event *ev, |
| 474 | struct ltt_kernel_channel *channel, |
| 475 | char *filter_expression, |
| 476 | struct lttng_filter_bytecode *filter) |
| 477 | { |
| 478 | int err, fd; |
| 479 | enum lttng_error_code ret; |
| 480 | struct ltt_kernel_event *event; |
| 481 | |
| 482 | assert(ev); |
| 483 | assert(channel); |
| 484 | |
| 485 | /* We pass ownership of filter_expression and filter */ |
| 486 | ret = trace_kernel_create_event(ev, filter_expression, |
| 487 | filter, &event); |
| 488 | if (ret != LTTNG_OK) { |
| 489 | goto error; |
| 490 | } |
| 491 | |
| 492 | fd = kernctl_create_event(channel->fd, event->event); |
| 493 | if (fd < 0) { |
| 494 | switch (-fd) { |
| 495 | case EEXIST: |
| 496 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 497 | break; |
| 498 | case ENOSYS: |
| 499 | WARN("Event type not implemented"); |
| 500 | ret = LTTNG_ERR_KERN_EVENT_ENOSYS; |
| 501 | break; |
| 502 | case ENOENT: |
| 503 | WARN("Event %s not found!", ev->name); |
| 504 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 505 | break; |
| 506 | default: |
| 507 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 508 | PERROR("create event ioctl"); |
| 509 | } |
| 510 | goto free_event; |
| 511 | } |
| 512 | |
| 513 | event->type = ev->type; |
| 514 | event->fd = fd; |
| 515 | /* Prevent fd duplication after execlp() */ |
| 516 | err = fcntl(event->fd, F_SETFD, FD_CLOEXEC); |
| 517 | if (err < 0) { |
| 518 | PERROR("fcntl session fd"); |
| 519 | } |
| 520 | |
| 521 | if (filter) { |
| 522 | err = kernctl_filter(event->fd, filter); |
| 523 | if (err < 0) { |
| 524 | switch (-err) { |
| 525 | case ENOMEM: |
| 526 | ret = LTTNG_ERR_FILTER_NOMEM; |
| 527 | break; |
| 528 | default: |
| 529 | ret = LTTNG_ERR_FILTER_INVAL; |
| 530 | break; |
| 531 | } |
| 532 | goto filter_error; |
| 533 | } |
| 534 | } |
| 535 | |
| 536 | if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) { |
| 537 | ret = userspace_probe_event_add_callsites(ev, channel->session, |
| 538 | event->fd); |
| 539 | if (ret) { |
| 540 | goto add_callsite_error; |
| 541 | } |
| 542 | } |
| 543 | |
| 544 | err = kernctl_enable(event->fd); |
| 545 | if (err < 0) { |
| 546 | switch (-err) { |
| 547 | case EEXIST: |
| 548 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 549 | break; |
| 550 | default: |
| 551 | PERROR("enable kernel event"); |
| 552 | ret = LTTNG_ERR_KERN_ENABLE_FAIL; |
| 553 | break; |
| 554 | } |
| 555 | goto enable_error; |
| 556 | } |
| 557 | |
| 558 | /* Add event to event list */ |
| 559 | cds_list_add(&event->list, &channel->events_list.head); |
| 560 | channel->event_count++; |
| 561 | |
| 562 | DBG("Event %s created (fd: %d)", ev->name, event->fd); |
| 563 | |
| 564 | return 0; |
| 565 | |
| 566 | add_callsite_error: |
| 567 | enable_error: |
| 568 | filter_error: |
| 569 | { |
| 570 | int closeret; |
| 571 | |
| 572 | closeret = close(event->fd); |
| 573 | if (closeret) { |
| 574 | PERROR("close event fd"); |
| 575 | } |
| 576 | } |
| 577 | free_event: |
| 578 | free(event); |
| 579 | error: |
| 580 | return ret; |
| 581 | } |
| 582 | |
| 583 | /* |
| 584 | * Disable a kernel channel. |
| 585 | */ |
| 586 | int kernel_disable_channel(struct ltt_kernel_channel *chan) |
| 587 | { |
| 588 | int ret; |
| 589 | |
| 590 | assert(chan); |
| 591 | |
| 592 | ret = kernctl_disable(chan->fd); |
| 593 | if (ret < 0) { |
| 594 | PERROR("disable chan ioctl"); |
| 595 | goto error; |
| 596 | } |
| 597 | |
| 598 | chan->enabled = 0; |
| 599 | DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")", |
| 600 | chan->channel->name, chan->fd, chan->key); |
| 601 | |
| 602 | return 0; |
| 603 | |
| 604 | error: |
| 605 | return ret; |
| 606 | } |
| 607 | |
| 608 | /* |
| 609 | * Enable a kernel channel. |
| 610 | */ |
| 611 | int kernel_enable_channel(struct ltt_kernel_channel *chan) |
| 612 | { |
| 613 | int ret; |
| 614 | |
| 615 | assert(chan); |
| 616 | |
| 617 | ret = kernctl_enable(chan->fd); |
| 618 | if (ret < 0 && ret != -EEXIST) { |
| 619 | PERROR("Enable kernel chan"); |
| 620 | goto error; |
| 621 | } |
| 622 | |
| 623 | chan->enabled = 1; |
| 624 | DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")", |
| 625 | chan->channel->name, chan->fd, chan->key); |
| 626 | |
| 627 | return 0; |
| 628 | |
| 629 | error: |
| 630 | return ret; |
| 631 | } |
| 632 | |
| 633 | /* |
| 634 | * Enable a kernel event. |
| 635 | */ |
| 636 | int kernel_enable_event(struct ltt_kernel_event *event) |
| 637 | { |
| 638 | int ret; |
| 639 | |
| 640 | assert(event); |
| 641 | |
| 642 | ret = kernctl_enable(event->fd); |
| 643 | if (ret < 0) { |
| 644 | switch (-ret) { |
| 645 | case EEXIST: |
| 646 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 647 | break; |
| 648 | default: |
| 649 | PERROR("enable kernel event"); |
| 650 | break; |
| 651 | } |
| 652 | goto error; |
| 653 | } |
| 654 | |
| 655 | event->enabled = 1; |
| 656 | DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd); |
| 657 | |
| 658 | return 0; |
| 659 | |
| 660 | error: |
| 661 | return ret; |
| 662 | } |
| 663 | |
| 664 | /* |
| 665 | * Disable a kernel event. |
| 666 | */ |
| 667 | int kernel_disable_event(struct ltt_kernel_event *event) |
| 668 | { |
| 669 | int ret; |
| 670 | |
| 671 | assert(event); |
| 672 | |
| 673 | ret = kernctl_disable(event->fd); |
| 674 | if (ret < 0) { |
| 675 | switch (-ret) { |
| 676 | case EEXIST: |
| 677 | ret = LTTNG_ERR_KERN_EVENT_EXIST; |
| 678 | break; |
| 679 | default: |
| 680 | PERROR("disable kernel event"); |
| 681 | break; |
| 682 | } |
| 683 | goto error; |
| 684 | } |
| 685 | |
| 686 | event->enabled = 0; |
| 687 | DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd); |
| 688 | |
| 689 | return 0; |
| 690 | |
| 691 | error: |
| 692 | return ret; |
| 693 | } |
| 694 | |
| 695 | static |
| 696 | struct process_attr_tracker *_kernel_get_process_attr_tracker( |
| 697 | struct ltt_kernel_session *session, |
| 698 | enum lttng_process_attr process_attr) |
| 699 | { |
| 700 | switch (process_attr) { |
| 701 | case LTTNG_PROCESS_ATTR_PROCESS_ID: |
| 702 | return session->tracker_pid; |
| 703 | case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID: |
| 704 | return session->tracker_vpid; |
| 705 | case LTTNG_PROCESS_ATTR_USER_ID: |
| 706 | return session->tracker_uid; |
| 707 | case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID: |
| 708 | return session->tracker_vuid; |
| 709 | case LTTNG_PROCESS_ATTR_GROUP_ID: |
| 710 | return session->tracker_gid; |
| 711 | case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID: |
| 712 | return session->tracker_vgid; |
| 713 | default: |
| 714 | return NULL; |
| 715 | } |
| 716 | } |
| 717 | |
| 718 | const struct process_attr_tracker *kernel_get_process_attr_tracker( |
| 719 | struct ltt_kernel_session *session, |
| 720 | enum lttng_process_attr process_attr) |
| 721 | { |
| 722 | return (const struct process_attr_tracker *) |
| 723 | _kernel_get_process_attr_tracker(session, process_attr); |
| 724 | } |
| 725 | |
| 726 | enum lttng_error_code kernel_process_attr_tracker_set_tracking_policy( |
| 727 | struct ltt_kernel_session *session, |
| 728 | enum lttng_process_attr process_attr, |
| 729 | enum lttng_tracking_policy policy) |
| 730 | { |
| 731 | int ret; |
| 732 | enum lttng_error_code ret_code = LTTNG_OK; |
| 733 | struct process_attr_tracker *tracker = |
| 734 | _kernel_get_process_attr_tracker(session, process_attr); |
| 735 | enum lttng_tracking_policy previous_policy; |
| 736 | |
| 737 | if (!tracker) { |
| 738 | ret_code = LTTNG_ERR_INVALID; |
| 739 | goto end; |
| 740 | } |
| 741 | |
| 742 | previous_policy = process_attr_tracker_get_tracking_policy(tracker); |
| 743 | ret = process_attr_tracker_set_tracking_policy(tracker, policy); |
| 744 | if (ret) { |
| 745 | ret_code = LTTNG_ERR_UNK; |
| 746 | goto end; |
| 747 | } |
| 748 | |
| 749 | if (previous_policy == policy) { |
| 750 | goto end; |
| 751 | } |
| 752 | |
| 753 | switch (policy) { |
| 754 | case LTTNG_TRACKING_POLICY_INCLUDE_ALL: |
| 755 | if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) { |
| 756 | /* |
| 757 | * Maintain a special case for the process ID process |
| 758 | * attribute tracker as it was the only supported |
| 759 | * attribute prior to 2.12. |
| 760 | */ |
| 761 | ret = kernctl_track_pid(session->fd, -1); |
| 762 | } else { |
| 763 | ret = kernctl_track_id(session->fd, process_attr, -1); |
| 764 | } |
| 765 | break; |
| 766 | case LTTNG_TRACKING_POLICY_EXCLUDE_ALL: |
| 767 | case LTTNG_TRACKING_POLICY_INCLUDE_SET: |
| 768 | /* fall-through. */ |
| 769 | if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) { |
| 770 | /* |
| 771 | * Maintain a special case for the process ID process |
| 772 | * attribute tracker as it was the only supported |
| 773 | * attribute prior to 2.12. |
| 774 | */ |
| 775 | ret = kernctl_untrack_pid(session->fd, -1); |
| 776 | } else { |
| 777 | ret = kernctl_untrack_id(session->fd, process_attr, -1); |
| 778 | } |
| 779 | break; |
| 780 | default: |
| 781 | abort(); |
| 782 | } |
| 783 | /* kern-ctl error handling */ |
| 784 | switch (-ret) { |
| 785 | case 0: |
| 786 | ret_code = LTTNG_OK; |
| 787 | break; |
| 788 | case EINVAL: |
| 789 | ret_code = LTTNG_ERR_INVALID; |
| 790 | break; |
| 791 | case ENOMEM: |
| 792 | ret_code = LTTNG_ERR_NOMEM; |
| 793 | break; |
| 794 | case EEXIST: |
| 795 | ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS; |
| 796 | break; |
| 797 | default: |
| 798 | ret_code = LTTNG_ERR_UNK; |
| 799 | break; |
| 800 | } |
| 801 | end: |
| 802 | return ret_code; |
| 803 | } |
| 804 | |
| 805 | enum lttng_error_code kernel_process_attr_tracker_inclusion_set_add_value( |
| 806 | struct ltt_kernel_session *session, |
| 807 | enum lttng_process_attr process_attr, |
| 808 | const struct process_attr_value *value) |
| 809 | { |
| 810 | int ret, integral_value; |
| 811 | enum lttng_error_code ret_code; |
| 812 | struct process_attr_tracker *tracker; |
| 813 | enum process_attr_tracker_status status; |
| 814 | |
| 815 | /* |
| 816 | * Convert process attribute tracker value to the integral |
| 817 | * representation required by the kern-ctl API. |
| 818 | */ |
| 819 | switch (process_attr) { |
| 820 | case LTTNG_PROCESS_ATTR_PROCESS_ID: |
| 821 | case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID: |
| 822 | integral_value = (int) value->value.pid; |
| 823 | break; |
| 824 | case LTTNG_PROCESS_ATTR_USER_ID: |
| 825 | case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID: |
| 826 | if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) { |
| 827 | uid_t uid; |
| 828 | |
| 829 | ret_code = utils_user_id_from_name( |
| 830 | value->value.user_name, &uid); |
| 831 | if (ret_code != LTTNG_OK) { |
| 832 | goto end; |
| 833 | } |
| 834 | integral_value = (int) uid; |
| 835 | } else { |
| 836 | integral_value = (int) value->value.uid; |
| 837 | } |
| 838 | break; |
| 839 | case LTTNG_PROCESS_ATTR_GROUP_ID: |
| 840 | case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID: |
| 841 | if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) { |
| 842 | gid_t gid; |
| 843 | |
| 844 | ret_code = utils_group_id_from_name( |
| 845 | value->value.group_name, &gid); |
| 846 | if (ret_code != LTTNG_OK) { |
| 847 | goto end; |
| 848 | } |
| 849 | integral_value = (int) gid; |
| 850 | } else { |
| 851 | integral_value = (int) value->value.gid; |
| 852 | } |
| 853 | break; |
| 854 | default: |
| 855 | ret_code = LTTNG_ERR_INVALID; |
| 856 | goto end; |
| 857 | } |
| 858 | |
| 859 | tracker = _kernel_get_process_attr_tracker(session, process_attr); |
| 860 | if (!tracker) { |
| 861 | ret_code = LTTNG_ERR_INVALID; |
| 862 | goto end; |
| 863 | } |
| 864 | |
| 865 | status = process_attr_tracker_inclusion_set_add_value(tracker, value); |
| 866 | if (status != PROCESS_ATTR_TRACKER_STATUS_OK) { |
| 867 | switch (status) { |
| 868 | case PROCESS_ATTR_TRACKER_STATUS_EXISTS: |
| 869 | ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS; |
| 870 | break; |
| 871 | case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY: |
| 872 | ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY; |
| 873 | break; |
| 874 | case PROCESS_ATTR_TRACKER_STATUS_ERROR: |
| 875 | default: |
| 876 | ret_code = LTTNG_ERR_UNK; |
| 877 | break; |
| 878 | } |
| 879 | goto end; |
| 880 | } |
| 881 | |
| 882 | DBG("Kernel track %s %d for session id %" PRIu64, |
| 883 | lttng_process_attr_to_string(process_attr), |
| 884 | integral_value, session->id); |
| 885 | if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) { |
| 886 | /* |
| 887 | * Maintain a special case for the process ID process attribute |
| 888 | * tracker as it was the only supported attribute prior to 2.12. |
| 889 | */ |
| 890 | ret = kernctl_track_pid(session->fd, integral_value); |
| 891 | } else { |
| 892 | ret = kernctl_track_id( |
| 893 | session->fd, process_attr, integral_value); |
| 894 | } |
| 895 | if (ret == 0) { |
| 896 | ret_code = LTTNG_OK; |
| 897 | goto end; |
| 898 | } |
| 899 | |
| 900 | kernel_wait_quiescent(); |
| 901 | |
| 902 | /* kern-ctl error handling */ |
| 903 | switch (-ret) { |
| 904 | case 0: |
| 905 | ret_code = LTTNG_OK; |
| 906 | break; |
| 907 | case EINVAL: |
| 908 | ret_code = LTTNG_ERR_INVALID; |
| 909 | break; |
| 910 | case ENOMEM: |
| 911 | ret_code = LTTNG_ERR_NOMEM; |
| 912 | break; |
| 913 | case EEXIST: |
| 914 | ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS; |
| 915 | break; |
| 916 | default: |
| 917 | ret_code = LTTNG_ERR_UNK; |
| 918 | break; |
| 919 | } |
| 920 | |
| 921 | /* Attempt to remove the value from the tracker. */ |
| 922 | status = process_attr_tracker_inclusion_set_remove_value( |
| 923 | tracker, value); |
| 924 | if (status != PROCESS_ATTR_TRACKER_STATUS_OK) { |
| 925 | ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error", |
| 926 | lttng_process_attr_to_string(process_attr), |
| 927 | integral_value); |
| 928 | } |
| 929 | end: |
| 930 | return ret_code; |
| 931 | } |
| 932 | |
| 933 | enum lttng_error_code kernel_process_attr_tracker_inclusion_set_remove_value( |
| 934 | struct ltt_kernel_session *session, |
| 935 | enum lttng_process_attr process_attr, |
| 936 | const struct process_attr_value *value) |
| 937 | { |
| 938 | int ret, integral_value; |
| 939 | enum lttng_error_code ret_code; |
| 940 | struct process_attr_tracker *tracker; |
| 941 | enum process_attr_tracker_status status; |
| 942 | |
| 943 | /* |
| 944 | * Convert process attribute tracker value to the integral |
| 945 | * representation required by the kern-ctl API. |
| 946 | */ |
| 947 | switch (process_attr) { |
| 948 | case LTTNG_PROCESS_ATTR_PROCESS_ID: |
| 949 | case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID: |
| 950 | integral_value = (int) value->value.pid; |
| 951 | break; |
| 952 | case LTTNG_PROCESS_ATTR_USER_ID: |
| 953 | case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID: |
| 954 | if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) { |
| 955 | uid_t uid; |
| 956 | |
| 957 | ret_code = utils_user_id_from_name( |
| 958 | value->value.user_name, &uid); |
| 959 | if (ret_code != LTTNG_OK) { |
| 960 | goto end; |
| 961 | } |
| 962 | integral_value = (int) uid; |
| 963 | } else { |
| 964 | integral_value = (int) value->value.uid; |
| 965 | } |
| 966 | break; |
| 967 | case LTTNG_PROCESS_ATTR_GROUP_ID: |
| 968 | case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID: |
| 969 | if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) { |
| 970 | gid_t gid; |
| 971 | |
| 972 | ret_code = utils_group_id_from_name( |
| 973 | value->value.group_name, &gid); |
| 974 | if (ret_code != LTTNG_OK) { |
| 975 | goto end; |
| 976 | } |
| 977 | integral_value = (int) gid; |
| 978 | } else { |
| 979 | integral_value = (int) value->value.gid; |
| 980 | } |
| 981 | break; |
| 982 | default: |
| 983 | ret_code = LTTNG_ERR_INVALID; |
| 984 | goto end; |
| 985 | } |
| 986 | |
| 987 | tracker = _kernel_get_process_attr_tracker(session, process_attr); |
| 988 | if (!tracker) { |
| 989 | ret_code = LTTNG_ERR_INVALID; |
| 990 | goto end; |
| 991 | } |
| 992 | |
| 993 | status = process_attr_tracker_inclusion_set_remove_value( |
| 994 | tracker, value); |
| 995 | if (status != PROCESS_ATTR_TRACKER_STATUS_OK) { |
| 996 | switch (status) { |
| 997 | case PROCESS_ATTR_TRACKER_STATUS_MISSING: |
| 998 | ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING; |
| 999 | break; |
| 1000 | case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY: |
| 1001 | ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY; |
| 1002 | break; |
| 1003 | case PROCESS_ATTR_TRACKER_STATUS_ERROR: |
| 1004 | default: |
| 1005 | ret_code = LTTNG_ERR_UNK; |
| 1006 | break; |
| 1007 | } |
| 1008 | goto end; |
| 1009 | } |
| 1010 | |
| 1011 | DBG("Kernel track %s %d for session id %" PRIu64, |
| 1012 | lttng_process_attr_to_string(process_attr), |
| 1013 | integral_value, session->id); |
| 1014 | if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) { |
| 1015 | /* |
| 1016 | * Maintain a special case for the process ID process attribute |
| 1017 | * tracker as it was the only supported attribute prior to 2.12. |
| 1018 | */ |
| 1019 | ret = kernctl_untrack_pid(session->fd, integral_value); |
| 1020 | } else { |
| 1021 | ret = kernctl_untrack_id( |
| 1022 | session->fd, process_attr, integral_value); |
| 1023 | } |
| 1024 | if (ret == 0) { |
| 1025 | ret_code = LTTNG_OK; |
| 1026 | goto end; |
| 1027 | } |
| 1028 | kernel_wait_quiescent(); |
| 1029 | |
| 1030 | /* kern-ctl error handling */ |
| 1031 | switch (-ret) { |
| 1032 | case 0: |
| 1033 | ret_code = LTTNG_OK; |
| 1034 | break; |
| 1035 | case EINVAL: |
| 1036 | ret_code = LTTNG_ERR_INVALID; |
| 1037 | break; |
| 1038 | case ENOMEM: |
| 1039 | ret_code = LTTNG_ERR_NOMEM; |
| 1040 | break; |
| 1041 | case ENOENT: |
| 1042 | ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING; |
| 1043 | break; |
| 1044 | default: |
| 1045 | ret_code = LTTNG_ERR_UNK; |
| 1046 | break; |
| 1047 | } |
| 1048 | |
| 1049 | /* Attempt to add the value to the tracker. */ |
| 1050 | status = process_attr_tracker_inclusion_set_add_value( |
| 1051 | tracker, value); |
| 1052 | if (status != PROCESS_ATTR_TRACKER_STATUS_OK) { |
| 1053 | ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error", |
| 1054 | lttng_process_attr_to_string(process_attr), |
| 1055 | integral_value); |
| 1056 | } |
| 1057 | end: |
| 1058 | return ret_code; |
| 1059 | } |
| 1060 | |
| 1061 | /* |
| 1062 | * Create kernel metadata, open from the kernel tracer and add it to the |
| 1063 | * kernel session. |
| 1064 | */ |
| 1065 | int kernel_open_metadata(struct ltt_kernel_session *session) |
| 1066 | { |
| 1067 | int ret; |
| 1068 | struct ltt_kernel_metadata *lkm = NULL; |
| 1069 | |
| 1070 | assert(session); |
| 1071 | |
| 1072 | /* Allocate kernel metadata */ |
| 1073 | lkm = trace_kernel_create_metadata(); |
| 1074 | if (lkm == NULL) { |
| 1075 | goto error; |
| 1076 | } |
| 1077 | |
| 1078 | /* Kernel tracer metadata creation */ |
| 1079 | ret = kernctl_open_metadata(session->fd, &lkm->conf->attr); |
| 1080 | if (ret < 0) { |
| 1081 | goto error_open; |
| 1082 | } |
| 1083 | |
| 1084 | lkm->fd = ret; |
| 1085 | lkm->key = ++next_kernel_channel_key; |
| 1086 | /* Prevent fd duplication after execlp() */ |
| 1087 | ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC); |
| 1088 | if (ret < 0) { |
| 1089 | PERROR("fcntl session fd"); |
| 1090 | } |
| 1091 | |
| 1092 | session->metadata = lkm; |
| 1093 | |
| 1094 | DBG("Kernel metadata opened (fd: %d)", lkm->fd); |
| 1095 | |
| 1096 | return 0; |
| 1097 | |
| 1098 | error_open: |
| 1099 | trace_kernel_destroy_metadata(lkm); |
| 1100 | error: |
| 1101 | return -1; |
| 1102 | } |
| 1103 | |
| 1104 | /* |
| 1105 | * Start tracing session. |
| 1106 | */ |
| 1107 | int kernel_start_session(struct ltt_kernel_session *session) |
| 1108 | { |
| 1109 | int ret; |
| 1110 | |
| 1111 | assert(session); |
| 1112 | |
| 1113 | ret = kernctl_start_session(session->fd); |
| 1114 | if (ret < 0) { |
| 1115 | PERROR("ioctl start session"); |
| 1116 | goto error; |
| 1117 | } |
| 1118 | |
| 1119 | DBG("Kernel session started"); |
| 1120 | |
| 1121 | return 0; |
| 1122 | |
| 1123 | error: |
| 1124 | return ret; |
| 1125 | } |
| 1126 | |
| 1127 | /* |
| 1128 | * Make a kernel wait to make sure in-flight probe have completed. |
| 1129 | */ |
| 1130 | void kernel_wait_quiescent(void) |
| 1131 | { |
| 1132 | int ret; |
| 1133 | int fd = kernel_tracer_fd; |
| 1134 | |
| 1135 | DBG("Kernel quiescent wait on %d", fd); |
| 1136 | |
| 1137 | ret = kernctl_wait_quiescent(fd); |
| 1138 | if (ret < 0) { |
| 1139 | PERROR("wait quiescent ioctl"); |
| 1140 | ERR("Kernel quiescent wait failed"); |
| 1141 | } |
| 1142 | } |
| 1143 | |
| 1144 | /* |
| 1145 | * Force flush buffer of metadata. |
| 1146 | */ |
| 1147 | int kernel_metadata_flush_buffer(int fd) |
| 1148 | { |
| 1149 | int ret; |
| 1150 | |
| 1151 | DBG("Kernel flushing metadata buffer on fd %d", fd); |
| 1152 | |
| 1153 | ret = kernctl_buffer_flush(fd); |
| 1154 | if (ret < 0) { |
| 1155 | ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret); |
| 1156 | } |
| 1157 | |
| 1158 | return 0; |
| 1159 | } |
| 1160 | |
| 1161 | /* |
| 1162 | * Force flush buffer for channel. |
| 1163 | */ |
| 1164 | int kernel_flush_buffer(struct ltt_kernel_channel *channel) |
| 1165 | { |
| 1166 | int ret; |
| 1167 | struct ltt_kernel_stream *stream; |
| 1168 | |
| 1169 | assert(channel); |
| 1170 | |
| 1171 | DBG("Flush buffer for channel %s", channel->channel->name); |
| 1172 | |
| 1173 | cds_list_for_each_entry(stream, &channel->stream_list.head, list) { |
| 1174 | DBG("Flushing channel stream %d", stream->fd); |
| 1175 | ret = kernctl_buffer_flush(stream->fd); |
| 1176 | if (ret < 0) { |
| 1177 | PERROR("ioctl"); |
| 1178 | ERR("Fail to flush buffer for stream %d (ret: %d)", |
| 1179 | stream->fd, ret); |
| 1180 | } |
| 1181 | } |
| 1182 | |
| 1183 | return 0; |
| 1184 | } |
| 1185 | |
| 1186 | /* |
| 1187 | * Stop tracing session. |
| 1188 | */ |
| 1189 | int kernel_stop_session(struct ltt_kernel_session *session) |
| 1190 | { |
| 1191 | int ret; |
| 1192 | |
| 1193 | assert(session); |
| 1194 | |
| 1195 | ret = kernctl_stop_session(session->fd); |
| 1196 | if (ret < 0) { |
| 1197 | goto error; |
| 1198 | } |
| 1199 | |
| 1200 | DBG("Kernel session stopped"); |
| 1201 | |
| 1202 | return 0; |
| 1203 | |
| 1204 | error: |
| 1205 | return ret; |
| 1206 | } |
| 1207 | |
| 1208 | /* |
| 1209 | * Open stream of channel, register it to the kernel tracer and add it |
| 1210 | * to the stream list of the channel. |
| 1211 | * |
| 1212 | * Note: given that the streams may appear in random order wrt CPU |
| 1213 | * number (e.g. cpu hotplug), the index value of the stream number in |
| 1214 | * the stream name is not necessarily linked to the CPU number. |
| 1215 | * |
| 1216 | * Return the number of created stream. Else, a negative value. |
| 1217 | */ |
| 1218 | int kernel_open_channel_stream(struct ltt_kernel_channel *channel) |
| 1219 | { |
| 1220 | int ret; |
| 1221 | struct ltt_kernel_stream *lks; |
| 1222 | |
| 1223 | assert(channel); |
| 1224 | |
| 1225 | while ((ret = kernctl_create_stream(channel->fd)) >= 0) { |
| 1226 | lks = trace_kernel_create_stream(channel->channel->name, |
| 1227 | channel->stream_count); |
| 1228 | if (lks == NULL) { |
| 1229 | ret = close(ret); |
| 1230 | if (ret) { |
| 1231 | PERROR("close"); |
| 1232 | } |
| 1233 | goto error; |
| 1234 | } |
| 1235 | |
| 1236 | lks->fd = ret; |
| 1237 | /* Prevent fd duplication after execlp() */ |
| 1238 | ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC); |
| 1239 | if (ret < 0) { |
| 1240 | PERROR("fcntl session fd"); |
| 1241 | } |
| 1242 | |
| 1243 | lks->tracefile_size = channel->channel->attr.tracefile_size; |
| 1244 | lks->tracefile_count = channel->channel->attr.tracefile_count; |
| 1245 | |
| 1246 | /* Add stream to channel stream list */ |
| 1247 | cds_list_add(&lks->list, &channel->stream_list.head); |
| 1248 | channel->stream_count++; |
| 1249 | |
| 1250 | DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd, |
| 1251 | lks->state); |
| 1252 | } |
| 1253 | |
| 1254 | return channel->stream_count; |
| 1255 | |
| 1256 | error: |
| 1257 | return -1; |
| 1258 | } |
| 1259 | |
| 1260 | /* |
| 1261 | * Open the metadata stream and set it to the kernel session. |
| 1262 | */ |
| 1263 | int kernel_open_metadata_stream(struct ltt_kernel_session *session) |
| 1264 | { |
| 1265 | int ret; |
| 1266 | |
| 1267 | assert(session); |
| 1268 | |
| 1269 | ret = kernctl_create_stream(session->metadata->fd); |
| 1270 | if (ret < 0) { |
| 1271 | PERROR("kernel create metadata stream"); |
| 1272 | goto error; |
| 1273 | } |
| 1274 | |
| 1275 | DBG("Kernel metadata stream created (fd: %d)", ret); |
| 1276 | session->metadata_stream_fd = ret; |
| 1277 | /* Prevent fd duplication after execlp() */ |
| 1278 | ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC); |
| 1279 | if (ret < 0) { |
| 1280 | PERROR("fcntl session fd"); |
| 1281 | } |
| 1282 | |
| 1283 | return 0; |
| 1284 | |
| 1285 | error: |
| 1286 | return -1; |
| 1287 | } |
| 1288 | |
| 1289 | /* |
| 1290 | * Get the event list from the kernel tracer and return the number of elements. |
| 1291 | */ |
| 1292 | ssize_t kernel_list_events(struct lttng_event **events) |
| 1293 | { |
| 1294 | int fd, ret; |
| 1295 | char *event; |
| 1296 | size_t nbmem, count = 0; |
| 1297 | FILE *fp; |
| 1298 | struct lttng_event *elist; |
| 1299 | |
| 1300 | assert(events); |
| 1301 | |
| 1302 | fd = kernctl_tracepoint_list(kernel_tracer_fd); |
| 1303 | if (fd < 0) { |
| 1304 | PERROR("kernel tracepoint list"); |
| 1305 | goto error; |
| 1306 | } |
| 1307 | |
| 1308 | fp = fdopen(fd, "r"); |
| 1309 | if (fp == NULL) { |
| 1310 | PERROR("kernel tracepoint list fdopen"); |
| 1311 | goto error_fp; |
| 1312 | } |
| 1313 | |
| 1314 | /* |
| 1315 | * Init memory size counter |
| 1316 | * See kernel-ctl.h for explanation of this value |
| 1317 | */ |
| 1318 | nbmem = KERNEL_EVENT_INIT_LIST_SIZE; |
| 1319 | elist = zmalloc(sizeof(struct lttng_event) * nbmem); |
| 1320 | if (elist == NULL) { |
| 1321 | PERROR("alloc list events"); |
| 1322 | count = -ENOMEM; |
| 1323 | goto end; |
| 1324 | } |
| 1325 | |
| 1326 | while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) { |
| 1327 | if (count >= nbmem) { |
| 1328 | struct lttng_event *new_elist; |
| 1329 | size_t new_nbmem; |
| 1330 | |
| 1331 | new_nbmem = nbmem << 1; |
| 1332 | DBG("Reallocating event list from %zu to %zu bytes", |
| 1333 | nbmem, new_nbmem); |
| 1334 | new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event)); |
| 1335 | if (new_elist == NULL) { |
| 1336 | PERROR("realloc list events"); |
| 1337 | free(event); |
| 1338 | free(elist); |
| 1339 | count = -ENOMEM; |
| 1340 | goto end; |
| 1341 | } |
| 1342 | /* Zero the new memory */ |
| 1343 | memset(new_elist + nbmem, 0, |
| 1344 | (new_nbmem - nbmem) * sizeof(struct lttng_event)); |
| 1345 | nbmem = new_nbmem; |
| 1346 | elist = new_elist; |
| 1347 | } |
| 1348 | strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN); |
| 1349 | elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 1350 | elist[count].enabled = -1; |
| 1351 | count++; |
| 1352 | free(event); |
| 1353 | } |
| 1354 | |
| 1355 | *events = elist; |
| 1356 | DBG("Kernel list events done (%zu events)", count); |
| 1357 | end: |
| 1358 | ret = fclose(fp); /* closes both fp and fd */ |
| 1359 | if (ret) { |
| 1360 | PERROR("fclose"); |
| 1361 | } |
| 1362 | return count; |
| 1363 | |
| 1364 | error_fp: |
| 1365 | ret = close(fd); |
| 1366 | if (ret) { |
| 1367 | PERROR("close"); |
| 1368 | } |
| 1369 | error: |
| 1370 | return -1; |
| 1371 | } |
| 1372 | |
| 1373 | /* |
| 1374 | * Get kernel version and validate it. |
| 1375 | */ |
| 1376 | int kernel_validate_version(struct lttng_kernel_tracer_version *version, |
| 1377 | struct lttng_kernel_tracer_abi_version *abi_version) |
| 1378 | { |
| 1379 | int ret; |
| 1380 | |
| 1381 | ret = kernctl_tracer_version(kernel_tracer_fd, version); |
| 1382 | if (ret < 0) { |
| 1383 | ERR("Failed to retrieve the lttng-modules version"); |
| 1384 | goto error; |
| 1385 | } |
| 1386 | |
| 1387 | /* Validate version */ |
| 1388 | if (version->major != VERSION_MAJOR) { |
| 1389 | ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)", |
| 1390 | version->major, VERSION_MAJOR); |
| 1391 | goto error_version; |
| 1392 | } |
| 1393 | ret = kernctl_tracer_abi_version(kernel_tracer_fd, abi_version); |
| 1394 | if (ret < 0) { |
| 1395 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1396 | goto error; |
| 1397 | } |
| 1398 | if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) { |
| 1399 | ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)", |
| 1400 | abi_version->major, abi_version->minor, |
| 1401 | LTTNG_MODULES_ABI_MAJOR_VERSION); |
| 1402 | goto error; |
| 1403 | } |
| 1404 | DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)", |
| 1405 | version->major, version->minor, |
| 1406 | abi_version->major, abi_version->minor); |
| 1407 | return 0; |
| 1408 | |
| 1409 | error_version: |
| 1410 | ret = -1; |
| 1411 | |
| 1412 | error: |
| 1413 | ERR("Kernel tracer version check failed; kernel tracing will not be available"); |
| 1414 | return ret; |
| 1415 | } |
| 1416 | |
| 1417 | /* |
| 1418 | * Kernel work-arounds called at the start of sessiond main(). |
| 1419 | */ |
| 1420 | int init_kernel_workarounds(void) |
| 1421 | { |
| 1422 | int ret; |
| 1423 | FILE *fp; |
| 1424 | |
| 1425 | /* |
| 1426 | * boot_id needs to be read once before being used concurrently |
| 1427 | * to deal with a Linux kernel race. A fix is proposed for |
| 1428 | * upstream, but the work-around is needed for older kernels. |
| 1429 | */ |
| 1430 | fp = fopen("/proc/sys/kernel/random/boot_id", "r"); |
| 1431 | if (!fp) { |
| 1432 | goto end_boot_id; |
| 1433 | } |
| 1434 | while (!feof(fp)) { |
| 1435 | char buf[37] = ""; |
| 1436 | |
| 1437 | ret = fread(buf, 1, sizeof(buf), fp); |
| 1438 | if (ret < 0) { |
| 1439 | /* Ignore error, we don't really care */ |
| 1440 | } |
| 1441 | } |
| 1442 | ret = fclose(fp); |
| 1443 | if (ret) { |
| 1444 | PERROR("fclose"); |
| 1445 | } |
| 1446 | end_boot_id: |
| 1447 | return 0; |
| 1448 | } |
| 1449 | |
| 1450 | /* |
| 1451 | * Teardown of a kernel session, keeping data required by destroy notifiers. |
| 1452 | */ |
| 1453 | void kernel_destroy_session(struct ltt_kernel_session *ksess) |
| 1454 | { |
| 1455 | struct lttng_trace_chunk *trace_chunk; |
| 1456 | |
| 1457 | if (ksess == NULL) { |
| 1458 | DBG3("No kernel session when tearing down session"); |
| 1459 | return; |
| 1460 | } |
| 1461 | |
| 1462 | DBG("Tearing down kernel session"); |
| 1463 | trace_chunk = ksess->current_trace_chunk; |
| 1464 | |
| 1465 | /* |
| 1466 | * Destroy channels on the consumer if at least one FD has been sent and we |
| 1467 | * are in no output mode because the streams are in *no* monitor mode so we |
| 1468 | * have to send a command to clean them up or else they leaked. |
| 1469 | */ |
| 1470 | if (!ksess->output_traces && ksess->consumer_fds_sent) { |
| 1471 | int ret; |
| 1472 | struct consumer_socket *socket; |
| 1473 | struct lttng_ht_iter iter; |
| 1474 | |
| 1475 | /* For each consumer socket. */ |
| 1476 | rcu_read_lock(); |
| 1477 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1478 | socket, node.node) { |
| 1479 | struct ltt_kernel_channel *chan; |
| 1480 | |
| 1481 | /* For each channel, ask the consumer to destroy it. */ |
| 1482 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1483 | ret = kernel_consumer_destroy_channel(socket, chan); |
| 1484 | if (ret < 0) { |
| 1485 | /* Consumer is probably dead. Use next socket. */ |
| 1486 | continue; |
| 1487 | } |
| 1488 | } |
| 1489 | } |
| 1490 | rcu_read_unlock(); |
| 1491 | } |
| 1492 | |
| 1493 | /* Close any relayd session */ |
| 1494 | consumer_output_send_destroy_relayd(ksess->consumer); |
| 1495 | |
| 1496 | trace_kernel_destroy_session(ksess); |
| 1497 | lttng_trace_chunk_put(trace_chunk); |
| 1498 | } |
| 1499 | |
| 1500 | /* Teardown of data required by destroy notifiers. */ |
| 1501 | void kernel_free_session(struct ltt_kernel_session *ksess) |
| 1502 | { |
| 1503 | if (ksess == NULL) { |
| 1504 | return; |
| 1505 | } |
| 1506 | trace_kernel_free_session(ksess); |
| 1507 | } |
| 1508 | |
| 1509 | /* |
| 1510 | * Destroy a kernel channel object. It does not do anything on the tracer side. |
| 1511 | */ |
| 1512 | void kernel_destroy_channel(struct ltt_kernel_channel *kchan) |
| 1513 | { |
| 1514 | struct ltt_kernel_session *ksess = NULL; |
| 1515 | |
| 1516 | assert(kchan); |
| 1517 | assert(kchan->channel); |
| 1518 | |
| 1519 | DBG3("Kernel destroy channel %s", kchan->channel->name); |
| 1520 | |
| 1521 | /* Update channel count of associated session. */ |
| 1522 | if (kchan->session) { |
| 1523 | /* Keep pointer reference so we can update it after the destroy. */ |
| 1524 | ksess = kchan->session; |
| 1525 | } |
| 1526 | |
| 1527 | trace_kernel_destroy_channel(kchan); |
| 1528 | |
| 1529 | /* |
| 1530 | * At this point the kernel channel is not visible anymore. This is safe |
| 1531 | * since in order to work on a visible kernel session, the tracing session |
| 1532 | * lock (ltt_session.lock) MUST be acquired. |
| 1533 | */ |
| 1534 | if (ksess) { |
| 1535 | ksess->channel_count--; |
| 1536 | } |
| 1537 | } |
| 1538 | |
| 1539 | /* |
| 1540 | * Take a snapshot for a given kernel session. |
| 1541 | * |
| 1542 | * Return LTTNG_OK on success or else return a LTTNG_ERR code. |
| 1543 | */ |
| 1544 | enum lttng_error_code kernel_snapshot_record( |
| 1545 | struct ltt_kernel_session *ksess, |
| 1546 | const struct consumer_output *output, int wait, |
| 1547 | uint64_t nb_packets_per_stream) |
| 1548 | { |
| 1549 | int err, ret, saved_metadata_fd; |
| 1550 | enum lttng_error_code status = LTTNG_OK; |
| 1551 | struct consumer_socket *socket; |
| 1552 | struct lttng_ht_iter iter; |
| 1553 | struct ltt_kernel_metadata *saved_metadata; |
| 1554 | char *trace_path = NULL; |
| 1555 | size_t consumer_path_offset = 0; |
| 1556 | |
| 1557 | assert(ksess); |
| 1558 | assert(ksess->consumer); |
| 1559 | assert(output); |
| 1560 | |
| 1561 | DBG("Kernel snapshot record started"); |
| 1562 | |
| 1563 | /* Save current metadata since the following calls will change it. */ |
| 1564 | saved_metadata = ksess->metadata; |
| 1565 | saved_metadata_fd = ksess->metadata_stream_fd; |
| 1566 | |
| 1567 | rcu_read_lock(); |
| 1568 | |
| 1569 | ret = kernel_open_metadata(ksess); |
| 1570 | if (ret < 0) { |
| 1571 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1572 | goto error; |
| 1573 | } |
| 1574 | |
| 1575 | ret = kernel_open_metadata_stream(ksess); |
| 1576 | if (ret < 0) { |
| 1577 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1578 | goto error_open_stream; |
| 1579 | } |
| 1580 | |
| 1581 | trace_path = setup_channel_trace_path(ksess->consumer, |
| 1582 | DEFAULT_KERNEL_TRACE_DIR, &consumer_path_offset); |
| 1583 | if (!trace_path) { |
| 1584 | status = LTTNG_ERR_INVALID; |
| 1585 | goto error; |
| 1586 | } |
| 1587 | /* Send metadata to consumer and snapshot everything. */ |
| 1588 | cds_lfht_for_each_entry(output->socks->ht, &iter.iter, |
| 1589 | socket, node.node) { |
| 1590 | struct ltt_kernel_channel *chan; |
| 1591 | |
| 1592 | pthread_mutex_lock(socket->lock); |
| 1593 | /* This stream must not be monitored by the consumer. */ |
| 1594 | ret = kernel_consumer_add_metadata(socket, ksess, 0); |
| 1595 | pthread_mutex_unlock(socket->lock); |
| 1596 | if (ret < 0) { |
| 1597 | status = LTTNG_ERR_KERN_META_FAIL; |
| 1598 | goto error_consumer; |
| 1599 | } |
| 1600 | |
| 1601 | /* For each channel, ask the consumer to snapshot it. */ |
| 1602 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1603 | status = consumer_snapshot_channel(socket, chan->key, output, 0, |
| 1604 | ksess->uid, ksess->gid, |
| 1605 | &trace_path[consumer_path_offset], wait, |
| 1606 | nb_packets_per_stream); |
| 1607 | if (status != LTTNG_OK) { |
| 1608 | (void) kernel_consumer_destroy_metadata(socket, |
| 1609 | ksess->metadata); |
| 1610 | goto error_consumer; |
| 1611 | } |
| 1612 | } |
| 1613 | |
| 1614 | /* Snapshot metadata, */ |
| 1615 | status = consumer_snapshot_channel(socket, ksess->metadata->key, output, |
| 1616 | 1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset], |
| 1617 | wait, 0); |
| 1618 | if (status != LTTNG_OK) { |
| 1619 | goto error_consumer; |
| 1620 | } |
| 1621 | |
| 1622 | /* |
| 1623 | * The metadata snapshot is done, ask the consumer to destroy it since |
| 1624 | * it's not monitored on the consumer side. |
| 1625 | */ |
| 1626 | (void) kernel_consumer_destroy_metadata(socket, ksess->metadata); |
| 1627 | } |
| 1628 | |
| 1629 | error_consumer: |
| 1630 | /* Close newly opened metadata stream. It's now on the consumer side. */ |
| 1631 | err = close(ksess->metadata_stream_fd); |
| 1632 | if (err < 0) { |
| 1633 | PERROR("close snapshot kernel"); |
| 1634 | } |
| 1635 | |
| 1636 | error_open_stream: |
| 1637 | trace_kernel_destroy_metadata(ksess->metadata); |
| 1638 | error: |
| 1639 | /* Restore metadata state.*/ |
| 1640 | ksess->metadata = saved_metadata; |
| 1641 | ksess->metadata_stream_fd = saved_metadata_fd; |
| 1642 | rcu_read_unlock(); |
| 1643 | free(trace_path); |
| 1644 | return status; |
| 1645 | } |
| 1646 | |
| 1647 | /* |
| 1648 | * Get the syscall mask array from the kernel tracer. |
| 1649 | * |
| 1650 | * Return 0 on success else a negative value. In both case, syscall_mask should |
| 1651 | * be freed. |
| 1652 | */ |
| 1653 | int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits) |
| 1654 | { |
| 1655 | assert(syscall_mask); |
| 1656 | assert(nr_bits); |
| 1657 | |
| 1658 | return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits); |
| 1659 | } |
| 1660 | |
| 1661 | static |
| 1662 | int kernel_tracer_abi_greater_or_equal(unsigned int major, unsigned int minor) |
| 1663 | { |
| 1664 | int ret; |
| 1665 | struct lttng_kernel_tracer_abi_version abi; |
| 1666 | |
| 1667 | ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi); |
| 1668 | if (ret < 0) { |
| 1669 | ERR("Failed to retrieve lttng-modules ABI version"); |
| 1670 | goto error; |
| 1671 | } |
| 1672 | |
| 1673 | ret = abi.major > major || (abi.major == major && abi.minor >= minor); |
| 1674 | error: |
| 1675 | return ret; |
| 1676 | } |
| 1677 | |
| 1678 | /* |
| 1679 | * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi |
| 1680 | * version number. |
| 1681 | * |
| 1682 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1683 | * of errors. |
| 1684 | */ |
| 1685 | int kernel_supports_ring_buffer_snapshot_sample_positions(void) |
| 1686 | { |
| 1687 | /* |
| 1688 | * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3 |
| 1689 | */ |
| 1690 | return kernel_tracer_abi_greater_or_equal(2, 3); |
| 1691 | } |
| 1692 | |
| 1693 | /* |
| 1694 | * Check for the support of the packet sequence number via abi version number. |
| 1695 | * |
| 1696 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1697 | * of errors. |
| 1698 | */ |
| 1699 | int kernel_supports_ring_buffer_packet_sequence_number(void) |
| 1700 | { |
| 1701 | /* |
| 1702 | * Packet sequence number was introduced in LTTng 2.8, |
| 1703 | * lttng-modules ABI 2.1. |
| 1704 | */ |
| 1705 | return kernel_tracer_abi_greater_or_equal(2, 1); |
| 1706 | } |
| 1707 | |
| 1708 | /* |
| 1709 | * Check for the support of event notifiers via abi version number. |
| 1710 | * |
| 1711 | * Return 1 on success, 0 when feature is not supported, negative value in case |
| 1712 | * of errors. |
| 1713 | */ |
| 1714 | int kernel_supports_event_notifiers(void) |
| 1715 | { |
| 1716 | /* |
| 1717 | * Event notifiers were introduced in LTTng 2.13, lttng-modules ABI 2.6. |
| 1718 | */ |
| 1719 | return kernel_tracer_abi_greater_or_equal(2, 6); |
| 1720 | } |
| 1721 | |
| 1722 | /* |
| 1723 | * Rotate a kernel session. |
| 1724 | * |
| 1725 | * Return LTTNG_OK on success or else an LTTng error code. |
| 1726 | */ |
| 1727 | enum lttng_error_code kernel_rotate_session(struct ltt_session *session) |
| 1728 | { |
| 1729 | int ret; |
| 1730 | enum lttng_error_code status = LTTNG_OK; |
| 1731 | struct consumer_socket *socket; |
| 1732 | struct lttng_ht_iter iter; |
| 1733 | struct ltt_kernel_session *ksess = session->kernel_session; |
| 1734 | |
| 1735 | assert(ksess); |
| 1736 | assert(ksess->consumer); |
| 1737 | |
| 1738 | DBG("Rotate kernel session %s started (session %" PRIu64 ")", |
| 1739 | session->name, session->id); |
| 1740 | |
| 1741 | rcu_read_lock(); |
| 1742 | |
| 1743 | /* |
| 1744 | * Note that this loop will end after one iteration given that there is |
| 1745 | * only one kernel consumer. |
| 1746 | */ |
| 1747 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1748 | socket, node.node) { |
| 1749 | struct ltt_kernel_channel *chan; |
| 1750 | |
| 1751 | /* For each channel, ask the consumer to rotate it. */ |
| 1752 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1753 | DBG("Rotate kernel channel %" PRIu64 ", session %s", |
| 1754 | chan->key, session->name); |
| 1755 | ret = consumer_rotate_channel(socket, chan->key, |
| 1756 | ksess->uid, ksess->gid, ksess->consumer, |
| 1757 | /* is_metadata_channel */ false); |
| 1758 | if (ret < 0) { |
| 1759 | status = LTTNG_ERR_ROTATION_FAIL_CONSUMER; |
| 1760 | goto error; |
| 1761 | } |
| 1762 | } |
| 1763 | |
| 1764 | /* |
| 1765 | * Rotate the metadata channel. |
| 1766 | */ |
| 1767 | ret = consumer_rotate_channel(socket, ksess->metadata->key, |
| 1768 | ksess->uid, ksess->gid, ksess->consumer, |
| 1769 | /* is_metadata_channel */ true); |
| 1770 | if (ret < 0) { |
| 1771 | status = LTTNG_ERR_ROTATION_FAIL_CONSUMER; |
| 1772 | goto error; |
| 1773 | } |
| 1774 | } |
| 1775 | |
| 1776 | error: |
| 1777 | rcu_read_unlock(); |
| 1778 | return status; |
| 1779 | } |
| 1780 | |
| 1781 | enum lttng_error_code kernel_create_channel_subdirectories( |
| 1782 | const struct ltt_kernel_session *ksess) |
| 1783 | { |
| 1784 | enum lttng_error_code ret = LTTNG_OK; |
| 1785 | enum lttng_trace_chunk_status chunk_status; |
| 1786 | |
| 1787 | rcu_read_lock(); |
| 1788 | assert(ksess->current_trace_chunk); |
| 1789 | |
| 1790 | /* |
| 1791 | * Create the index subdirectory which will take care |
| 1792 | * of implicitly creating the channel's path. |
| 1793 | */ |
| 1794 | chunk_status = lttng_trace_chunk_create_subdirectory( |
| 1795 | ksess->current_trace_chunk, |
| 1796 | DEFAULT_KERNEL_TRACE_DIR "/" DEFAULT_INDEX_DIR); |
| 1797 | if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) { |
| 1798 | ret = LTTNG_ERR_CREATE_DIR_FAIL; |
| 1799 | goto error; |
| 1800 | } |
| 1801 | error: |
| 1802 | rcu_read_unlock(); |
| 1803 | return ret; |
| 1804 | } |
| 1805 | |
| 1806 | /* |
| 1807 | * Setup necessary data for kernel tracer action. |
| 1808 | */ |
| 1809 | LTTNG_HIDDEN |
| 1810 | int init_kernel_tracer(void) |
| 1811 | { |
| 1812 | int ret; |
| 1813 | bool is_root = !getuid(); |
| 1814 | |
| 1815 | /* Modprobe lttng kernel modules */ |
| 1816 | ret = modprobe_lttng_control(); |
| 1817 | if (ret < 0) { |
| 1818 | goto error; |
| 1819 | } |
| 1820 | |
| 1821 | /* Open debugfs lttng */ |
| 1822 | kernel_tracer_fd = open(module_proc_lttng, O_RDWR); |
| 1823 | if (kernel_tracer_fd < 0) { |
| 1824 | DBG("Failed to open %s", module_proc_lttng); |
| 1825 | goto error_open; |
| 1826 | } |
| 1827 | |
| 1828 | /* Validate kernel version */ |
| 1829 | ret = kernel_validate_version(&kernel_tracer_version, |
| 1830 | &kernel_tracer_abi_version); |
| 1831 | if (ret < 0) { |
| 1832 | goto error_version; |
| 1833 | } |
| 1834 | |
| 1835 | ret = modprobe_lttng_data(); |
| 1836 | if (ret < 0) { |
| 1837 | goto error_modules; |
| 1838 | } |
| 1839 | |
| 1840 | ret = kernel_supports_ring_buffer_snapshot_sample_positions(); |
| 1841 | if (ret < 0) { |
| 1842 | goto error_modules; |
| 1843 | } |
| 1844 | |
| 1845 | if (ret < 1) { |
| 1846 | WARN("Kernel tracer does not support buffer monitoring. " |
| 1847 | "The monitoring timer of channels in the kernel domain " |
| 1848 | "will be set to 0 (disabled)."); |
| 1849 | } |
| 1850 | |
| 1851 | DBG("Kernel tracer fd %d", kernel_tracer_fd); |
| 1852 | |
| 1853 | ret = syscall_init_table(kernel_tracer_fd); |
| 1854 | if (ret < 0) { |
| 1855 | ERR("Unable to populate syscall table. Syscall tracing won't " |
| 1856 | "work for this session daemon."); |
| 1857 | } |
| 1858 | return 0; |
| 1859 | |
| 1860 | error_version: |
| 1861 | modprobe_remove_lttng_control(); |
| 1862 | ret = close(kernel_tracer_fd); |
| 1863 | if (ret) { |
| 1864 | PERROR("close"); |
| 1865 | } |
| 1866 | kernel_tracer_fd = -1; |
| 1867 | return LTTNG_ERR_KERN_VERSION; |
| 1868 | |
| 1869 | error_modules: |
| 1870 | ret = close(kernel_tracer_fd); |
| 1871 | if (ret) { |
| 1872 | PERROR("close"); |
| 1873 | } |
| 1874 | |
| 1875 | error_open: |
| 1876 | modprobe_remove_lttng_control(); |
| 1877 | |
| 1878 | error: |
| 1879 | WARN("No kernel tracer available"); |
| 1880 | kernel_tracer_fd = -1; |
| 1881 | if (!is_root) { |
| 1882 | return LTTNG_ERR_NEED_ROOT_SESSIOND; |
| 1883 | } else { |
| 1884 | return LTTNG_ERR_KERN_NA; |
| 1885 | } |
| 1886 | } |
| 1887 | |
| 1888 | LTTNG_HIDDEN |
| 1889 | void cleanup_kernel_tracer(void) |
| 1890 | { |
| 1891 | int ret; |
| 1892 | |
| 1893 | DBG2("Closing kernel fd"); |
| 1894 | if (kernel_tracer_fd >= 0) { |
| 1895 | ret = close(kernel_tracer_fd); |
| 1896 | if (ret) { |
| 1897 | PERROR("close"); |
| 1898 | } |
| 1899 | kernel_tracer_fd = -1; |
| 1900 | } |
| 1901 | DBG("Unloading kernel modules"); |
| 1902 | modprobe_remove_lttng_all(); |
| 1903 | free(syscall_table); |
| 1904 | } |
| 1905 | |
| 1906 | LTTNG_HIDDEN |
| 1907 | bool kernel_tracer_is_initialized(void) |
| 1908 | { |
| 1909 | return kernel_tracer_fd >= 0; |
| 1910 | } |
| 1911 | |
| 1912 | /* |
| 1913 | * Clear a kernel session. |
| 1914 | * |
| 1915 | * Return LTTNG_OK on success or else an LTTng error code. |
| 1916 | */ |
| 1917 | enum lttng_error_code kernel_clear_session(struct ltt_session *session) |
| 1918 | { |
| 1919 | int ret; |
| 1920 | enum lttng_error_code status = LTTNG_OK; |
| 1921 | struct consumer_socket *socket; |
| 1922 | struct lttng_ht_iter iter; |
| 1923 | struct ltt_kernel_session *ksess = session->kernel_session; |
| 1924 | |
| 1925 | assert(ksess); |
| 1926 | assert(ksess->consumer); |
| 1927 | |
| 1928 | DBG("Clear kernel session %s (session %" PRIu64 ")", |
| 1929 | session->name, session->id); |
| 1930 | |
| 1931 | rcu_read_lock(); |
| 1932 | |
| 1933 | if (ksess->active) { |
| 1934 | ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id); |
| 1935 | status = LTTNG_ERR_FATAL; |
| 1936 | goto end; |
| 1937 | } |
| 1938 | |
| 1939 | /* |
| 1940 | * Note that this loop will end after one iteration given that there is |
| 1941 | * only one kernel consumer. |
| 1942 | */ |
| 1943 | cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter, |
| 1944 | socket, node.node) { |
| 1945 | struct ltt_kernel_channel *chan; |
| 1946 | |
| 1947 | /* For each channel, ask the consumer to clear it. */ |
| 1948 | cds_list_for_each_entry(chan, &ksess->channel_list.head, list) { |
| 1949 | DBG("Clear kernel channel %" PRIu64 ", session %s", |
| 1950 | chan->key, session->name); |
| 1951 | ret = consumer_clear_channel(socket, chan->key); |
| 1952 | if (ret < 0) { |
| 1953 | goto error; |
| 1954 | } |
| 1955 | } |
| 1956 | |
| 1957 | if (!ksess->metadata) { |
| 1958 | /* |
| 1959 | * Nothing to do for the metadata. |
| 1960 | * This is a snapshot session. |
| 1961 | * The metadata is genererated on the fly. |
| 1962 | */ |
| 1963 | continue; |
| 1964 | } |
| 1965 | |
| 1966 | /* |
| 1967 | * Clear the metadata channel. |
| 1968 | * Metadata channel is not cleared per se but we still need to |
| 1969 | * perform a rotation operation on it behind the scene. |
| 1970 | */ |
| 1971 | ret = consumer_clear_channel(socket, ksess->metadata->key); |
| 1972 | if (ret < 0) { |
| 1973 | goto error; |
| 1974 | } |
| 1975 | } |
| 1976 | |
| 1977 | goto end; |
| 1978 | error: |
| 1979 | switch (-ret) { |
| 1980 | case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED: |
| 1981 | status = LTTNG_ERR_CLEAR_RELAY_DISALLOWED; |
| 1982 | break; |
| 1983 | default: |
| 1984 | status = LTTNG_ERR_CLEAR_FAIL_CONSUMER; |
| 1985 | break; |
| 1986 | } |
| 1987 | end: |
| 1988 | rcu_read_unlock(); |
| 1989 | return status; |
| 1990 | } |